Using nrc lexicon, score each report over time using a cumulative sum. The reports all trend downward using raw scores, indicating an overall negative tone. To help account for this, there is a pos_adj parameter that calculates the ratio of abs(sum(neg) / sum(pos)). Multiplying the positive scores by (some fraction of) this parameter helps boost those scores in relation to negative scores.
For each mission, chart out the ‘emotional balance’ of the team - the sum of sentiment words for each of the various emotional sentiments.